Data type: add cards script

DOC_MSE_VERSION: since 0.3.7

--Overview--

A script to add multiple cards to the set at once.

--Properties--
! Property	Type					Default		Description
| @name@	[[type:string]]				 		Name of this script; appears in the menu.
| @description@	[[type:string]]				@""@		Description of this script; appears in the status bar.
| @enabled@	[[type:scriptable]] [[type:boolean]]	@true@		Is this script enabled?
| @script@	[[type:script]]				 		Script that produces the cards.<br>
		 					 		This script should return a [[type:list]] of [[type:card]]s.
		 					 		The [[fun:new_card]] function can be used to make new cards.

--Example--
>add cards script:
>	name: &Basic Lands
>	description: Adds 5 basic lands to the set.
>	script:
>		[ new_card([name: "Plains",   super_type: "Basic Land", sub_type: "Plains"])
>		, new_card([name: "Island",   super_type: "Basic Land", sub_type: "Island"])
>		, new_card([name: "Swamp",    super_type: "Basic Land", sub_type: "Swamp"])
>		, new_card([name: "Mountain", super_type: "Basic Land", sub_type: "Mountain"])
>		, new_card([name: "Forest",   super_type: "Basic Land", sub_type: "Forest"])
>		]

When invoked, this script will add the five basic lands to the set.

